Disrupting gut bacteria may have an effect on the brain, and in turn, behavior, studies in animal suggest.
A 2011 study in mice found that animals given antibiotics (which kill gut bacteria) became less anxious, and when their gut bacteria was restored, so was their anxiety.
Mice given antibiotics also showed changes in their brain chemistry that have been linked to depression.
The researchers said they suspect the bacteria are producing chemicals that can access and influence the brain.
If gut bacteria play a role in human behavior, its possible that therapies that aim to restore normal gut flora, such as probiotics, may be helpful in correcting behavior and mood changes in people with gastrointestinal diseases, according to the researchers. However, it's not clear if the results apply to people.https://www.livescience.com/39444-gut-bacteria-health.html